<?php
//获取某个月的最后一天或某个月的天数
function getMonthLastDay ( $month, $year )
{
    switch ( $month )
    {
        case 4 :
        case 6 :
        case 9 :
        case 11 :
            $days = 30;
            break;
        case 2 :
            if ( $year % 4 == 0 )
            {
                if ( $year % 100 == 0 )
                {
                    $days = $year % 400 == 0 ? 29 : 28;
                }
                else
                {
                    $days = 29;
                }
            }
            else
            {
                $days = 28;
            }
            break;

        default :
            $days = 31;
            break;
    }
    return $days;
}